1. Field of the Invention
Titanium and alloys thereof have high melting points and high specific strengths and exhibit excellent resistance to oxidation at high temperatures up to 800.degree. C. and, owing to these outstanding qualities, are used as high-temperature structural materials and for the production of aerospace parts. Further, since they exhibit excellent resistance to the corrosion of acids and alkalis, they are used in the components of chemical equipment which handle such corrosive solutions.
This invention relates to cores for use in casting hollow parts made of titanium and alloys thereof.
2. Prior Art Statement
The present inventor investigated the core for casting of titanium and alloys thereof. These metals have high melting points, manifest activity at elevated temperatures, and react readily with refractory materials. As raw materials for cores for use in casting titanium and alloys thereof, alumina, calcia, and other materials using such metal oxides as a main component have been studied. Since calcia readily reacts with moisture in the atmosphere, cores made of calcia cannot easily retain their shape and stability. Cores of alumina have a problem in that they are difficult to remove from the cast products. No core effectively usable for the casting of titanium and alloys thereof has been developed to date. Since titanium and alloys thereof manifest outstanding mechanical properties even at high temperatures, it is desired to develop a core suitable for titanium and titanium alloy castings.